The present invention relates to a device for tensioning a flexible strip for securing a bony element to an implant, comprising a rod having a first end provided with means for bearing on the implant, a mobile part for attaching the flexible strip to a portion of the device and adjustable means for blocking the part that is mobile in translation relative to said portion of the device.
It is particularly importantly applicable, although not exclusively applicable, to the field of the straightening of the spinal column of a patient having abnormal curvature.
In this case, with the vertebrae not being correctly aligned relative to one another in relation to the vertebral axis, they exhibit mutual inclinations.
In order to straighten the assembly, it is known to reset the lateral edges of the vertebrae to a substantially equivalent distance, on all sides of the spinal column, by the use of rods linking together either are screws, that are inserted into the vertebrae themselves, or hooks that are introduced along the vertebral canal.
However, such devices present drawbacks because they are aggressive.
To mitigate these drawbacks, there has been proposed a flexible link for fixing the vertebra to the link part which is in turn fixed to the straightening rod.
Means for blocking the flexible link by reclosing the link part on the rod are then necessary.
The problem that the invention seeks to resolve is in this case that of the tensioning of this flexible link for fixing the vertebra to the link part.
In practice, it is important for the user, when fitting this link, to be able to gradually retighten the latter without in any way damaging the bony element which is then compressed by the flexible strip.
There are currently tensioning ancillaries provided with a rod, a part that is mobile in translation along the rod and an element mounted on the mobile part tending horizontally to separate the end of the rod from the part.
Such an ancillary does, however, present drawbacks.
It in fact entails pulling in the extension of the link itself which has to be twisted to be able to allow it to be tensioned.
Furthermore, no manual feedback of the tension is possible with such an instrument which thus requires, to avoid crushing the bony element, an adjustable dynamometric system making it possible to stop the tensioning beyond a certain determined value.